Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that was first discovered in association with the African form of Burkitt's lymphoma (BL). Subsequently, EBV infection is also found to be strongly associated with nasopharyngeal carcinoma (NPC).
It has been shown that the EBV genome can be detected in almost all NPC tissues collected in Southern China (Chen et al., Intervirology. 36(2):91-8 (1993); Dickens et al., J Clin Pathol. 45(5):396-7 (1992)). Consistent with these results, we have demonstrated that EBV DNA can be detected in the plasma of 96% of NPC patients but only 7% of healthy subjects at a much lower concentration (Lo et al., Cancer Res. 59(6):1188-91 (1999)). Moreover, the level of plasma EBV DNA, measured either before (Lo et al., Cancer Res. 60(24):6878-81 (2000)) or after treatment (Chan et al., J Natl Cancer Inst. 94(21):1614-9 (2002)), is valuable for predicting the overall and disease-free survival. Similarly, circulating EBV DNA is also useful for the detection and monitoring of other EBV-associated malignancies, for example, lymphoma (Lei et al., Br J. Haematol. 111(1):239-46 (2000)) and gastric carcinoma (Lo et al., Clin Cancer Res. 7(7):1856-9 (2001)).
Although this plasma test is useful for the detection of NPC and is a relatively risk free procedure, it still causes pain and anxiety in patients. However, detection and/or quantification of short EBV associated nucleic acid sequences in a urine sample, as well as uses thereof, have not been disclosed in the art. Accordingly, there is a need for develop an alternative test for diagnosis, prognosis, and/or monitoring of EBV-associated cancers.